Well packer having two sets of slips



M. B. CONRAD 3,469,628

6 Sheets-Sheet l WELL PACKER HAVING TWO SETS OF SLIPS Sept. 30, 1969 Filed Jan. 2, 196s A TTOF/VEYS.'

Sept. 30, i969 M. a. coNRAD 3,459,628

WELL PACKER HAVING TWO SETS OF SLIPS Filed Jan. 2, 1968 6 Sheets-Sheet 2 INVENTOR A44/@77N 5. 60A/@A0 47 TOIQ/VEKS.

Sept. 30, i969 Filed Jan. 2, 1968 M. B. CONRAD WELL PACKER HAVING TWO SETS OF SLIPS JIL-5 6 lSheets-Sheet 3 BY Fl@ Sept 30, 19969 'M. acoNRAD 3,469,628.' l l WELL PACKER HAVING TWO SETS OF SLIPS 6 Sheets-Sheet 4 Filed Jan.

Sept. 30, i969 M. B. CONRAD WELL PACKER HAVING TWO SETS OF SLIPS 6 Sheets-Sheet 5 Filed Jan. 2, 1968 INVENTOR. MT/A/ `5. (0A/@.40

A Trae/vans'.

6 Sheets-Sheet 6 M. B. CONRAD WELL PACKER HAVING TWO SETS OF- SLIPS Sept. 30, i969 Filed J an. 2, 1968 United States Patent O M U.S. Cl. 166-134 15 Claims ABSTRACT OF THE DISCLOSURE A well packer including a mandrel carrying two inv dependent sets of slips and drag blocks together with axially compressible packing elements in between. The rst slips can be set by movement of the mandrel in one direction after it is within the well, also compressing the packing means to cause it to seal against the well casing. When the pressure on the packer exceeds a predetermined value, the tubing string elongates, the resulting movement of the mandrel releasing the iirst set of slips and setting the second set. The tool can be used with either end up, operating as either a tension or a compression tool. It is always free to move in one direction to free the tool in response to axial loading rather than rotation. The mandrel is in two sections threaded together, with a set of slips and drag blocks on each. The second mandrel section is coupled to the first slips so that with the lirst slips set the threaded joint between the mandrel sections may be separated to assure release of and retraction of both sets of slips during removal of the tool from the well.

BACKGROUND OF THE INVENTION The iield of the invention This invention relates to well packers.

The prior art In the past, there have been many packers designed in which the resilient element is compressed in response to movement of a mandrel in one direction. Conventional packers, however, have been devised to withstand maximum loads only from one direction. Also, they are not always releasable Without rotation. Moreover, they have not included means to assure that the gripping elements will be completely retracted during the retrieval of the packer from the well.

SUMMARY OF THE INVENTION The present invention provides a packer that will withstand high loading from both directions. This is accomplished through a transfer arrangement that includes two separate sets of slips on the mandrel. One set of slips will retain against a maximum force in one direction. When the force in the opposite direction exceeds a pre determined value, the load is transferred from these slips to a second set which will resist maximum loads in the opposite direction. This is accomplished through the use of a first drag block-and-slip assembly adjacent the opposite end. The compressible packing element is between the two sets of slips. The rst slips are set by moving the mandrel in one direction which, through appropriate shoulders, causes the expansion cone to urge the slips outwardly into gripping engagement with the well casing and also to compress the packing, causing it to expand outwardly and seal against the well casing. The first slips inherently will resist high loading in one direction, which merely sets the slips tighter. However, if the loading in the opposite direction should exceed a predetermined value, the tubing string stretches under the load, causing the mandrel to move so that the expansion cone releases the rst slips. This movement of the mandrel also moves the cone of the second set of slips so that it forces the 3,469,628 Patented Sept. 30, 1969 lCC second slips into gripping engagement with the well casing. When the transfer to the second set of slips occurs, the mandrel becomes loaded only in the amount necessary to eiect the elongation. Loads above that amount are taken directly by the second set of slips and not imposed on the mandrel.

The tool may be used with either end up, thereby being of great versatility. With one end up it functions as a tension tool, and when reversed in position it acts as a set-down tool. In either attitude it may be freed for retrieval in response to an axial force, with no rotation being required for initiating movement of the tool. Operation of the tool requires only a single control, rather than dual controls as for many tools.

The mandrel is in two sections threaded together. The section circumscribed by the second set of slips is coupled rotationally to the first set of slips. This permits this section to be held stationary, while rotation of the other section of the mandrel causes the threaded joint to be broken. Both sets of slips then may be so positioned that they cannot inadvertently become set during retrieval of the tool from the well, allowing rapid removal of the tool.

An object of this invention is to provide an improved well packer.

Another object of this invention is to provide a Well packer capable of withstanding loads applied from either end.

A further object of this invention is to provide a well packer having two gripping means arranged to transfer the holding force from one gripping means to the other under load.

An additional object of this invention is to provide a well packer that can be used with either end up.

Yet another object of this invention is to provide a well packer that always is free to move in one direction in response to a load imposed upon it, not requiring rotation to free the tool.

A still further object of this invention is to provide a well packer that can be placed in a safetied position for retrieval whereby it cannot be set inadvertently during removal from the well.

These and other objects will become apparent from the following detailed description taken in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIGURES la and 1b are longitudinal sectional views of the tool in the position in which it is run into the well;

FIGURES 2a and 2b are views similar to FIGURES la and 1b with one group of slips set;

FIGURES 3a and 3b are views similar to FIGURES la and 1b, but with the mandrel elongated and the load transferred to the second set of slips;

FIGURES 4a and 4b are views similar to FIGURES la and lb, but with the joint separated between the two sections of the mandrel so that the tool is safetied and the slips cannot be set;

FIGURE 5 is a side elevational View of the mandrel with surrounding components removed to illustrate the J- slot;

FIGURE 6 is a transverse sectional view taken along line 6-6 of FIGURE la;

FIGURE 7 is a transverse sectional view taken along line 7-7 of FIGURE 1b;

FIGURE 8 is a transverse sectional view taken along line 8-8 of FIGURE 1b;

FIGURE 9 is a transverse sectional view taken along line 9-9 of FIGURE 1b;

FIGURE 10 is a side elevational view illustrating the arrangement of the friction washer at the upper swivel joint;

FIGURE 11 is a fragmentary sectional view taken along line 11--11 of FIGURE la;

FIGURE l2 is a longitudinal View taken along line 12-12 of FIGURE 9, illustrating the arrangement for holding the lower slip-and-drag block assembly together; and

FIGURE 13 is a fragmentary longitudinal sectional view taken along line 13-13 of FIGURE 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The tool of this invention is carried by a tubing string 9, and includes a mandrel 10, which is made up of two sections. Usually it is positioned so that the section 11 of the mandrel is uppermost, threaded onto the end of the tubing string 9. The mandrel section 11 is connected by a threaded joint 12 to a lower section 13. Therefore, the rotary joint 12 is separable upon relative rotation in one direction of the sections 11 and 13. With the tool constructed as illustrated, a left-handed thread is used at the joint 12. An O-ring 14 at the joint 12 provides a seal.

Circumscribing the upper portion of the upper mandrel section 11 is a collar 15, the outer periphery of which is recessed to receive one ange of a ring 16, which is U-shaped in cross section. The flange at the other end of the ring 16 ts within a recess in the upper end of a tubular body member 17. The ring 16 thereby provides a swivel joint connecting the members 15 and 17, but allowing relative rotation between them.

The collar 15 carries keys 18 that extend inwardly into I-slots 19 in the surface of the mandrel. As shown in FIGURE la, FIGURE 6, and in solid lines in FIGURE 5, the keys 18 are in the lateral portions 20 of the l-slots rather than in the elongated main length 21 of the J-slots.

The upper end of the tubular body 17 is notched to receive a curved washer 22 which bears against both the member 17 and the lower end of the collar 15 (see FIG URE This provides a friction means that normally will prevent relative rotation between the collar and the tubular body 17. This allows the mandrel 10 to move the keys 18 into the different portions 20 and 21 of the I-slots 19 upon rotation of the mandrel. Nevertheless, the friction of the washer 22 may be overcome when it is necessary to operate the swivel joint.

The body member 17 constitutes a part of an upper drag block assembly 23 positioned on the mandrel section 11. Consequently, the member 17 is provided with a plurality of longitudinally extending recesses 24 which receive drag blocks 25 that are biased outwardly against the well casing 26 by means of springs 27. A sleeve member 28 positioned by screws 29, overlaps the upper ends of the recesses 24, while a similar sleeve 30 is positioned by screws 31 and overlaps the lower ends of the recesses 24, preventing separation of the drag blocks 25 from the member 17 when the tool is outside the well casing.

A second swivel joint 32 is provided between the drag block assembly 23 and an upper slip assembly 33. The swivel joint includes a ring member 34, U-shaped in cross section, that ts within a recess in the exterior of the end of the tubular body member 17 and also extends into a recess in the annular slip-retaining member 35. A plurality of slips 36 is carried by the member 35. The member 35 includes inclined T-shaped slots 37 that receive the base portions 38 of the slip members 36. The opposite ends of the slips 36 include inclined surfaces 39 which ride along the sloping surface 40 of the cone 41 used in expanding the slips outwardly when the slips are set against the casing. The cone 41 and retainer member 35 are held together against separation axially by a tubular member 43 having flanges 44 and 45 that t next to abutment shoulders on the members 35 and 43. The sli-ps 36 are received in recesses in the cone 41 that circumscribes the mandrel section. Outwardly facing wickers 42 are included on the slips 36 for engagement with the well casing 26 when the slips are moved outwardly. Details of such 4 a slip assembly 33 and of drag blocks similar to the assembly 23 may be found in Patent 3,135,329.

A tubular member 46 is threaded onto the cone 41 and provided with a ange 47 at its lower end. This ange overlaps the flange 48 of an annular member 49, thereby preventing separation of the member 46 from the member 49. A key 50 is included on the flange 47 of the tubular member 46, being received in a longitudinally extending elongated keyway 51 in the member 49, as seen in FIGURE 11. Hence, the members 46 and 49 are coupled rotationally.

The lower end of the annular member 49 includes a projection 52 threaded on both its inner and outer surfaces. This ts within a threaded opening dened by a gauge ring 53 and the upper end of a sleeve 54. The latter member, which is sealed relative to the section 11 by an O-ring 55, extends through elastomeric packing members 56, 57 and 53. The packing members are separated by rings 59 and 60, and a gauge ring 61 is positioned at the lower end of the packing member 58.

The lower end of the sleeve 54 includes an outwardly facing annular groove 62. A key 63 extends outwardly beyond the groove 62 at one location, as seen in FIGURE 7. The lower end of the sleeve 54 is circumscribed by a tubular member 64 which is threaded onto the gauge ring 61. The inner periphery of the tubular member 64 is provided with an elongated longitudinally extending key 65. A split annular member 66 ts in the groove l62 of the sleeve 54, projecting radially beyond the top of the groove. The two generally semicylindrical sections of the member 66 are located between the key 63 of the sleeve 54 and the key 65 of the tubular member 64. This couples the sleeve 54 to the tubular member 64 as torque will be transmitted through the key 65 to the split annular member 66 and the key 63 of the member 54. At the same time, the sleeve 54 and tubular member 64 may be moved longitudinally to telescope these two members.

A collar 67 is threaded onto the member 64, having a portion of reduced diameter at the bottom end providing a shoulder 68. The latter element is located adjacent radially outwardly extending lugs 69 on the upper end of the lower mandrel section 13. The lower surface 70 of the member 67 is frustoconical, sloping upwardly and outwardly from its lower edge. The lugs 69 of the lower mandrel section 13 it within axially extending slots 71 in the lower end of the tubular member 64 beyond its threaded connection to the collar 167 (see FIGURE 8). The effect is that of keying the lower mandrel section 13 to the tubular member 64 so that there is no relative rotation possible between these parts. The lugs 69, by engaging the shoulder 68, will not allow the mandrel section 13 to move downwardly relative to the member 67. Movement of the lower mandrel section 13 upwardly relative to the tubular member 64 from the position of FIGURE 1b is possible, however.

Below the member 67 on the mandrel section 13 is a combined drag-and-slip assembly 72. This unit includes a tubular housing 73 having longitudinally extending recesses 74 that receive drag blocks 75. These are generally similar to the drag blocks 25, being biased outwardly against the wall of the casing 26 by means of compression springs 76. Annular members 77 and 78 are located lat the ends of the tubular housing 73, and provided with anges 79 and 80 that overlap the recesses 74. This retains the drag blocks 75 so that they cannot become separated from the tubular housing 73 when the unit is removed from the well.

Interposed between the adjacent recesses 74 are additional recesses 81. These receive the elongated fingers 82 of slips 83. The upper ends of the slips 83 extend beyond the upper end of the tubular housing 73 and have wickers 84 on their outer surfaces. The inner surfaces 8S of the upper ends of the slips 83 are sloped, being generally complementary to the slope of the frustoconical section v70 of the member 67.

At its opposite end, each finger 82 is provided with an inwardly extending base portion 87 adjacent an outwardly extending abutment shoulder 88 on the housing 73. Beyond the base portion 87 of the slip 83 is an end section 89 engaged by a compression spring 90. The flange 80 of the annular member 78 overlaps the end section 89. The action of the spring 90, therefore, is to bias the end section 89 of the slip toward the ange 80. This, in turn, tends to rotate the slip members so that the upper end portions and the wickers 84 are drawn inwardly toward the mandrel and away from the well casing 26. Consequently, the slips 83 are urged to a normal retracted position such as shown in FIGURE 1b where the fingers 82 rest against the annular member 77 at recesses formed therein.

The slip-and-drag assembly is held together by a plurality of screws 91 which extend through the member 77 and whose threaded ends are received in tapped openings in the member 78 (see FIGURE 12).

The upper annular member 77 of the drag block-andslip assembly 72 is adjacent a downwardly facing annular shoulder 92 on the exterior of the lower mandrel section 13. This prevents upward movement of the slip-and-drag assembly 72 on the mandrel section 13 from the position shown in FIGURE lb. However, this assembly is slidable on the mandrel, and so may move in the opposite direcnon.

Below the assembly 72, as shown in FIGURE 3b, is a guide 94 made up of annular members 95 and 96 which are threaded together. A holding ring 97 is received within a recess in the periphery of the lower mandrel section 13 and is adjacent an upwardly facing shoulder 98 on the member 95 of the guide assembly 94, fitting within a recess Within the lower mandrel section 13 and a recess dened between the lower end of the member 95 and a notched portion of the member 96. The outside diameter of the guide is made as large as the largest gauge ring of the packing unit. When the tool is being run into the hole, the guide absorbs the end loads on the unit as may occur when obstructions are encountered. These loads are taken out through the shoulder 98 of the guide assembly into the holding ring 97 and from there to the lower mandrel section 13.

In use of the tool of this invention, it is run into the well with the parts in the relationship shown in FIG- URES la and lb. In other words, the slips 36 and 83 are retracted when the tool is being introduced into the well casing 26. Consequently, there is only the resistance to axial movement afforded by the friction of the drag blocks 25 and 75.

When the desired position in the hole has been reached, the tool is set to the position shown in FIGURES 2a and 2b. To accomplish this, rst the tool is rotated to separate the keys 18 from the lateral portions 20 of the I-slots 19. With the lateral portions positioned on the left side as illustrated in FIGURE 5, the mandrel is given left-hand torque, which shifts the keys 18 into the elongated portions 21 of the J-slots. The outer components of the tool below the swivel joint 32 are keyed to the mandrel and rotate with it during the turning of the tool to remove the key 18 from the J-slot. This rotation is permitted by the swivel joint 32 as the drag blocks 25 remain stationary. The keys 18 also are held motionless through the member 17 and the friction washer 22 that engages the collar which carries the keys.

After the rotation of the tool, tension is applied to the mandrel. This causes the mandrel to move upwardly relative to the portions of the tool that circumscribe it until the lugs 69 of the mandrel are brought into engagement with the shoulders 100 of the member `64 at the upper ends of the slots 71. Further upward movement, therefore, applies an axial load through the gauge ring 61 into the packing rings 56, 57 and 58 and into the slip assembly 33, which is resisted by the drag blocks 25. As the load is applied, the cone 41 is engaged by the upper end of the annular member 49 and caused to move upwardly relative to the slips 36, which are held against movement of the drag blocks 25. Consequently, the sloping surfaces 39 of the slips 36 ride along the correspondingly inclined surface 40 of the cone 41, thereby moving the slips outwardly so that the wickers 42 engage the wall of the casing 26. This sets the slips so that they grip the well casing 26.

The pull on the mandrel also causes the packing rings 56, 57 and 58 to be squeezed as the upper gauge ring 53 is prevented from upward movement after the slips are set. Therefore, the packing rings become compressed between the abutments formed by the gauge rings 53 and 61 and expand outwardly to engage and seal against the wall of the casing 26 as shown in FIGURES 2a and 2b.

Thus, the tool is packed olf by the upward tension applied to it. In this position, the tool will withstand high pressures from both above and below the packing. Even extremely high pressures beneath the tool will have no effect upon it, as it then will remain in the position of FIGURES 2a and 2b. Such pressures will only tend to pack the tool olf tighter and to keep the upper slips 36 held more firmly in engagement with the well casing.

When the tool is in the position of FIGURES 2a and 2b, exceptionally high pressures from above will cause the holding force to be transferred from the upper set of slips 36 to the lower slips 83. During this time, the packing elements 56, 57 and 58 will continue to be compressed, and the tool will remain packed olf. When this transfer occurs, the parts change from the position of FIGURES 2o and 2b to that of FIGURES 3a and 3b.

Pressures existing above the tool produce a downward force by reacting against a pressure area equal to the an nular area between the periphery of the upper mandrel section 11 and the wall of the well casing 26. This pressure reacts against the portion of the upper packing ring 56 which projects beyond the gauge ring 53 and pushes also on the upper end of the gauge ring 53, the member 49 and on the upper end of the sleeve 54. It is assured that pressure will react against the latter element by the inclusion of openings 102 in the wall of the member 49, allowing fluid communication to the space inside the member 49. This gives access to the upper end of the sleeve 54.

While the net downward load resulting from a pressure differential across the packing members acts upon the full area of the annulus between the mandrel and the casing 26, it is resisted by an upward force on a smaller area. The upward resisting force on the packing members is merely the equivalent to the radial area of the lower gauge ring 61. Thus, there is a greater net area of reaction on the upper end of the assembled packers than on the lower. This keeps the packing members compressed and sealed against the well casing during transfer from the position of FIGURES 2a and 2b to that of FIGURES 3a and 3b.

The net differential pressure on the tool from above will impose a load on the mandrel tending to stretch the tubing string 9. This load is applied through the packing elements 56, 57 and 58 to the gauge ring 61 and the tubular member 64 beneath it. The load is transmitted through the shoulder of the member 64 to react downwardly against the lugs 69 of the lower mandrel section 13. When the uid pressure from above exceeds that below by a certain value, the tubing string, and to some degree the mandrel as well, will commence to elongate. As this stretching occurs, the packing elements 56, 57 and 58 slide downwardly along the wall of the casing 26. As the packing members move, the gauge ring 53 moves the annular member 49 downwardly until the ange 48 of this member is brought into engagement with the flange 47 of the tubular member 46. Continued elongation then causes the member 46 to be pulled downwardly, which, in turn, moves the cone 41 in that direction. This shifts the cone 41 away from the upper slips 36. Thus, the up per slips 36 are released.

At the same time, however, the collar 67 is moved downwardly by the tubular member 64 toward the lower slips 83. This moves the frustoconical surface 70 toward the inclined surfaces 85 of the lower slips 83. As the surfaces 70 and 85 are brought into interengagement and further stretching of the tubing string 9 takes place, the slips 83, held against downward movement by the drag blocks 75, are forced outwardly so that their wickers 84 are set against the wall of the casing 26. The lower slips 83 are expanded into the set position only after the upper slips 36 are released. The lower slips 831 then carry the downward load from the pressure above the packings, elongation of the tubing string 9 ceases and the parts become stationary. Thus, the load is transferred from the upper slips 36 to the lower slips 83.

As this takes place, the packing rings 56, 57 and 58 always remain sealed against the casing due to the end compression loading on them, and the tool remains packed off as the load is transferred from one set of slips to the other. After the load has been transferred from the top slips 36 to the bottom slips 83, increased net pressures from above can be absorbed readily. Such added loading only will compress the packing rings further and will urge the slips 83 more tightly against the wall of the casing. One advantageous feature of the packer is that the mandrel becomes loaded only in the amount required to effect the elongation when the transfer from one set of slips to the other takes place. Loads ove'r this amount are taken directly by the lower lslips 83 and not imposed on the mandrel.

If the net loading from above lshould decrease below a critical amount, the load will transfer back to the top slips 36. The reduced loading will cause the tubing string to contract in length, so that the lower slips 83 are released as the member 67 is moved upwardly by the reaction of the mandrel lugs 69 against the shoulder 100. This also pushes upwardly through the packings S6, 57 and 58 and the annular member 49 against the cone 41. The latter member is moved against the inclined surfaces 39 of the slips 36, expanding the slips 36 outwardly into the set position. The cone 41 will not be moved upwardly until the upper end of the annular member 49 engages the cone after telescoping into the tubular member 46. This assures that the upper slips 36 will not become set before the lower slips 83 have been released.

The packer will transfer back and forth between the two sets of slips within the same area of the casing and will not shift its position beyond this area from repeated cycling. The telescoping of the tubular member 46 and the annular member 49, with their interengageable anges 47 and 48, provides an expansion joint that enables the top slips to remain in the same location in the casing as the transfer to the lower slips 83 takes place. The cone 41 will be moved away from the upper slips only after appreciable elongation of the tubing string, remaining stationary until the flange 48 is brought into contact with the flange 47 of the tubular member 46. This means that the cone 41 is moved thereafter only the limited amount necessary to release the slips 36 without pulling downwardly on the slips 36 and the drag block assembly 23.

Retrieval of the tool is effected quite easily when desired. First, the packer is unloaded either through use of an unloader or by otherwise balancing the pressure across it. After this, the tool is lifted up by pulling on the mandrel 10. This causes the lugs 69 of ythe mandrel to shift the member 67 and its cone surface 70 away from the lower slips 83. This releases the lower slips so that they no longer hold against the well casing and are retracted by the springs 90. Thus, both sets of slips are released and offer no resistance to movement of the -tool relative to the casing. Then, a sit-down load is applied to the mandrel, pushing the 1bottom slips down the hole gener- 8 ally to the position of FIGURES la and 1b. After that, right-hand rotation is applied to the mandrel, which brings the keys 18 back into the lateral portions 20 of the l-slots 19. At this point, the tool is ready to be retrieved from the lwell by pulling upwardly on the mandrel 10.

The packer may `be released and retrieved from the position of FIGURES 2a and 2b, in the event no transfer has taken place, merely by releasing the upward tension on the mandrel 10, moving the keys 18 back into the lateral I-slot portions 20 and pushing downwardly on the mandrel. This relieves the compression in the packing members 56, 57 and 5S. The downward movement of the mandrel causes the lugs 69 of the mandrel to pull downwardly on the members 67 and 64 and the gauge ring 61. The interference `between the gauge ring 61 and the split annular member 66 in the groove 62 of the sleeve 54, seen in FIGURE 13, causes the sleeve S4 also to be pulled downwardly. This, in turn, pulls downwardly on the annular member 49, which pulls on the tubular member 46 as the ilanges 48 and 47 are brought into engagement. The member 46 shifts the cone 41 away from the 'slips 36, returning the cone 41 to the position of FIG- URE la. This releases the slips 36 and frees the tool.

The tool of this invention may be placed in a safetied position, which precludes any inadvertent setting of the slips as it is removed. When in the safetied position, it may be pulled from the well as rapidly as desired. To place the tool in the safetied position, the steps described above for retrieval are followed to release the slips and to place the keys 18 into the J-slot portions 20. After that, preferably the tool is moved up and down the hole to make certain that it is free. Then, it is reset to the position of FIGURES 2a and 2b and a strain applied to the mandrel. Next, rotation is applied to the mandrel 10 to separate the threaded joint 12 where the upper mandrel section 11 joins the lower mandrel section 13. In the example shown, the mandrel is given right-hand rotation for this operation. When this rotational force is applied to the upper mandrel section 11, the lower mandrel section 13 is prevented from turning by the upper slips 36 so that the joint 12 may be unscrewed. The lower mandrel section 13 is coupled rotationally to the slips 36 so that the rotation of the lower mandrel portion is resisted.

When the lower mandrel portion 13 receives a torque load as the upper mandrel section is turned, the rotational force is applied through the lugs 69 at the upper end of the lower mandrel section 13 to the sidewalls of the slots 71 in the lower end of the tubular member 64. This force is transmitted from the member 64 along the sides of the elongated key 65 to the longitudinal edge of the split annular member 66. This transmits the force to the key 63 on the sleeve 54.

The joint at the extension S2 of the annular member 49 which is engaged by the upper end of the sleeve 54 is threaded so that it -will not become loosened by the direction of the rotational force applied to the sleeve 54 from the tubular member 64. Thus, if the mandrel is to be given a righthand rotation to separate the threaded joint 12, as in the present example, the threads at the extension 52 are made left-handed so that they will only be tightened by the torque.

The annular member 49 is coupled to the tubular member 46 above it. This comes about from the key 50 of the member 46 that is received in the keyway 51 of the member 49. Again, therefore, the rotational force is transmitted upwardly through the outer components of the tool. At the cone 41, lefthand threads are used, so that the rotational force is applied from the member 46 into the cone 41. The latter member, in turn, is coupled to the slips 36. With the slips 36 being set in the position of FIGURE 2a, they are locked against rotation. Therefore, there is a continuous means of resisting the rotational force on the lower mandrel section 13, which ultimately is transmitted to the slips 36. As a consequence,

9. the lower mandrel section 13 is held against movement, and the upper mandrel section 11 is rotated to separate the threaded joint 12.

As this rotation of the upper mandrel section 11 is accomplished, it is unnecessary to attempt to rotate the upper drag blocks 25. This is because of the presence of the upper swivel joint 16. Therefore, despite the fact that the keys 18 are rotated with the upper mandrel section 11, a 'swivel is provided at the member 16 so that the housing 17 and the upper drag blocks 25 remain sta- `tionary. The frictional resistance of the washer 22 is overcome as the upper mandrel section turns.

After the upper and lower mandrel sections have been separated, the tool may be -pulled from the well casing as the parts assume the position shown in FIGURES 4a and 4b. The upper mandrel section 11 is shifted upwardly until the keys 18 are brought to the bottom ends of the elongated J-slot portions 21. Continued upward movement of the mandrel section 11 causes the keys 1'8 to pull upwardly on the collar 15, likewise pulling on the tubular body 17, which, through the ring 34, pulls the member 35 upwardly. This releases the upper slips 36. The entire tool comes out as a unit, with both sets of slips retracted and positioned relative to their expansion cones so they cannot become reset.

The engagement of the keys 18 and the lower ends of the J-slots connects the drag `block assembly 23 and the slip assembly 33 to the upper mandrel section 11 for removal. The flange 47 of the tubular member 46 engages the ange 48 of the annular member 49 so that the packing elements and the members 64 and 67 are moved with ,the mandrel section 11.

The keys 18 contact the ends of the slots 21 only after the bottom end 103 of the upper mandrel section 11 has passed the O-ring 55 in the sleeve 54. Consequently, there is a free passageway for iluid through and around the tool as the device is pulled out of the hole. Because of this, there is no possibility of a hydraulic lock as the device is retrieved.

The lugs 69 of the lower mandrel section 13 engage -the shoulder 68 of the collar 67, which prevents the lower .mandrel section from being separated from the remainder of the tool. Also, the lower drag-and-slip assembly 72 is engaged by the guide assembly 94 at the lower end of the tool, which causes it to be pulled upwardly with the mandrel. In the unlikely occurrence that an obstruction should be encountered by the lower drag-and-slip assembly 72, the other elements of the tool can be pulled free, with only the assemblies 72 and 94 being lost. In such an event, the washer 99 will shear, allowing the assemblies 72 and 94 to slide olf the bottom end of the lower mandrel section 13.

The tool has been described above as a tension packer, with the mandrel section 11 constituting the upper end. However, it may be used as a set-down tool as well, with .the mandrel section 13 at the upper end. This renders the .tool quite versatile as it may be utilized either way and so satisfy particular circumstances or preferences. When the mandrel section 13 is at the upper end, the packer is set by a downward load on the mandrel. No rotation is required to retrieve the packer when it is used in this manner. In fact, when used either way, the tool always may be moved in the casing to free it by imposing an axial rather than a rotational load. The tool need not be safetied during retrievel when operated as a set-down packer .as it then cannot become set inadvertently when being a second gripping means on said body, a sealing means on said body,

said sealing means being compressible for engaging the wall of a well,

means for applying a force on said body in one direction,

said means for applying a force on said body including means on said body for so compressing said sealing means and moving said first gripping means into gripping engagement with the wall of a well receiving said body,

and means on said body for moving said second gripping means into gripping engagement with said wall of said well in response to a force on said body in another direction.

2. A well packer comprising a body adapted to be inserted into a well,

a first gripping means on said body,

a second gripping means on said body,

a compressible packing means on said body,

means for applying a force on said body in one direction,

said means for applying a force on said body in one direction including means on said body for compressing said packing means for bringing said packing means into sealing engagement with the wall of a well, said means for applying a force to said body in one direction including means on said body for moving said lirst gripping means into gripping engagement with said Wall of said well for holding said body therein, and elongatable means on said body responsive to pressure on said body through said packing means for moving said second gripping means into gripping engagement with said wall of said well.

3. A Well packer comprising a body adapted for insertion into a well bore,

compressible packing means on said body,

said packing means being normally retracted and expansible outwardly in response to compression thereof,

a rst gripping means on said body movable outwardly for gripping engagement with the wall of said well bore for holding said body therein,

a second gripping means on said body movable outwardly for engagement with said wall of said well bore for holding said body therein,

means for applying a force on said body in one direction,

said means for applying a force on said body including means for compressing said packing means, and further including means for so moving said rst gripping means outwardly,

and means on said body for releasing said first gripping means and subsequently so moving said second gripping means outwardly while maintaining said packing means so compressed upon the imposition of a predetermined force on said body in the opposite direction.

4. A well packer comprising a body adapted to be inserted into a well,

a -rst gripping means on said body,

a second gripping means on said body,

a first expansion means on said body for moving said dirst gripping means into gripping engagement with the wall of a well for holding said body therein,

a second expansion means on said body for moving said second gripping means into gripping engagement with said wall of said well for holding said body therein,

packing means on said body,

said packing means being normally retracted, and

being movable outwardly into sealing engagement with said wall of said well in response to compression thereof,

means on said body responsive to a force applied to said body for causing said first expansion means to so move said first gripping means into gripping engagement with said wall of said well and for compressing said packing means for so moving said packing means into sealing engagement with said wall of said well, and means responsive to pressure on said body for releasing said first gripping means and causing said second expansion means to so move said second gripping means into gripping engagement with said wall of said well.

5. A well packer comprising a body adapted to be inserted into a well,

a compressible packing means on said body expansible outwardly into sealing engagement with a well bore upon the compression thereof,

a first gripping means on said body on one side of said packing means,

a second gripping means on said body on the opposite side of said packing means,

a first expansion means for moving said first gripping means into gripping engagement with the wall of a well and holding said body therein,

a second expansion means for moving said second gripping means into gripping engagement with said Wall of said well and holding said body therein,

means on said body responsive to a force applied to said body in one direction for causing said first expansion means to so move said first gripping means into sealing engagement with said wall of said Well and for so compressing said packing means,

said body being elongatable upon the imposition of a predetermined pressure on said packing means when so compressed for producing a force on said body in the opposite direction,

and means on said body for releasing said first gripping means upon said elongation of said body and for subsequently causing said second expansion means to so expand said second gripping means into gripping engagement with said wall of said well.

6. A packer comprising an elongated mandrel,

a first slip means on said mandrel,

a second slip means on said mandrel,

a compressible packing means on said mandrel intermediate said slip means,

means for moving said rfirst slip means outwardly for gripping engagement with a well casing upon movement of said mandrel in one direction,

abutment means on said mandrel for compressing said packing means for expanding said packing means outwardly for engagement with said well casing upon said movement of said mandrel in said one direction,

said mandrel being adapted for attachment to a tubing string elongatable upon the imposition of a predetermined force in the opposite direction on said abutment means through said packing means subsequent to said compression of said packing means,

thereby moving said mandrel in said opposite direction,

said means for moving said first slip means outwardly including means for releasing said first slip means upon said movement of said mandrel in said opposite direction,

and means on said mandrel for moving said second slip means outwardly into gripping engagement with a well casing upon said movement of said mandrel in said opposite direction for thereby transferring the gripping of said well casing from said first slip means to said second slip means.

7. A device as recited in claim 6 in which said means for moving said first slip means includes a member having a surface engageable with said first slip means for so moving said first slip means outwardly,

and said means for releasing said first slip means including an abutment engageable with said member upon a predetermined amount of said movement of said mandrel in said opposite direction for moving said member therewith upon subsequent movement of said mandrel in said opposite direction for moving said surface relative to said first slip means,

said means for moving said second slip means outwardly being operative only subsequent to such movement of said member by said abutment sufficient to move said surface relative to said first slip means so as to release said first slip means.

8. A device as recited in claim 6 in which said second slip means includes an element circumscribing said mandrel,

a plurality of elongated members carried by saidl element,

one end portion of each of said elongated members having outwardly facing wickers thereon,

and resilient means engaging the opposite end of each of said elongated members for producing a force biasing said one end portions inwardly to a normal retracted position.

9. A well packer comprising an elongated mandrel,

said mandrel including a first section and a second section,

joint means interconnecting said first and second sections,

said joint means being separable upon relative rotation of said first and second sections in one rotary direction,

gripping means on said mandrel,

compressible packing means on said mandrel,

means on said mandrel for moving said gripping means outwardly into gripping engagement with a Well casing upon movement of said mandrel in one direction, means on said mandrel for compressing vsaid packing `means upon said movement of said mandrel in said one direction for expanding said packing means outwardly into sealing engagement with said well casing, means coupling said second section to said gripping means,

whereby upon rotation of said first section in said one rotary direction said gripping means when so expanded outwardly prevent rotation of said second section and said joint means thereby becomes separated,

and means on said mandrel for releasing said gripping means upon said separation of said joint means for thereby permiting retrieval of said packer with said gripping means so released.

10. A well packer comprising a body adapted to be inserted into a well,

said body including a first section a section,

and a rotary joint interconnecting said first and second sections,

a first gripping means on said first section,

a second gripping means in said second section,

a first expansion means on said first section for moving said first gripping means into gripping engagement with the wall of a Well for holding said body therein,

a second expansion means on said second section for moving said second gripping means into gripping engagement with said wall of said Well for holding said lbody therein,

packing means on said body movable into sealing engagement with said wall of said well,

means on said body responsive to a force applied to said body for causing said first expansion means to so move said first gripping means into gripping engagement with said wall of said well,

and for so moving said packing means into sealing engagement with said wall of said well,

13 means on said body responsive to pressureon said body for causing said second expansion means to so move said second gripping means into gripping engagement with said wall of said well, means coupling said second section to said first gripping means whereby when said first gripping means is in gripping engagement with said wall of said well said second section is held from rotation and rotation of said first section separates said rotary joint, and means on said body for releasing said first gripping means and preventing said first and second gripping means from being moved into said gripping engagement with said wall of said well subsequent to said separation of said joint. 11. A packer comprising an elongated mandrel,

said mandrel including a first section, a second section, and joint means connecting said first and second sections, said joint means being separable upon rotation of one of said sections relative to the other of said sections, a duality of slip means,

the first of said slip means being on said first section, the second of said slip means being on said second section, compressible packing means on said first section, abutment means on said first section for applying a force to move said first slip means outwardly into gripping engagement with the Wall of a well casing receiving the same upon the application of an axial force in one direction to said mandrel.

and for compressing said packing means upon the application of such an axial force for expansion of said packing means outwardly into sealing engagement with said well casing, j said mandrel being adapted for attachment to a tubing string which is elongatable upon the application of a force of a predetermined magnitude against said packing means in the opposite direction, f thereby to move said mandrel in said opposite direction, means on said mandrel for releasing said first slip means upon said movement of said mandrel in said opposite direction and for moving said second slip means outwardly for gripping engagement with said wall of said well casing,

for thereby transferring the gripping engagement with said wall of said well casing fromfsaid rst slip means to said second slip means.' means coupling said first slip means to said second mandrel section so that when said first slip means are in said gripping engagement with said wall of said well casing said second mandrel section is prevented from rotation and rotation of said first mandrel section will cause said joint means between said mandrel sections to become disconnected, and means on said mandrel for releasing said first slip means upon the application of an axial force to said first mandrel section subsequent to the disconnection of said joint means. 12. In combination with a tubing string, a well packer comprising an elongated mandrel attached to said tubing string, a resilient compressible packing means on said mandrel, a first drag block means on said mandrel on one side of said packing means, a plurality of first slips on said mandrel adjacent said first drag block means, an expansion member on said mandrel between said first slips and said packing means and movable tward said first slips for expanding said first slips outwardly into engagement with a well casing for gripping said well casing,

a plurality of second slips on said mandrel on the opposite side of said packing means,

said second slips being movable relative to said mandrel,

a second drag block means on said mandrel adjacent said second slips,

" abutment means adjacent said packing means on said opposite side thereof,

said abutment means being movable by said mandrel toward said first drag `block means upon movement of said mandrel in one direction,

whereby said abutment means moves said packing means and said expansion member and causes said expansion member to expand said first slips outwardly for gripping engagement with said well casing, and further causes said packing means to become compressed for expanding said packing means outwardly into Isealing engagement with said well casing,

'said tubing string being elongatable in response to a predetermined force in the opposite direction thereon resulting from a predetermined load in said opposite direction on said packing means when so compressed applied through` said abutmentmeans to said mandrel and from said mandrel to said tubing string,

thereby to move said mandrel opposite direction,

said expansion member being movable with said mandrel upon said movement in said apposite direction of said mandrel,

said expansion member being thereby moved away from said first slips for releasing said first slips from said gripping engagement with said well casing,

in said and a second expansion member adjacent saidsecond slips,

said second expansion member being movable with said mandrel toward said second slips upon said movement of said mandrel in said opposite direction for thereby expanding said second slips outwardly into gripping engagement with said well casing for thereby transferring said gripping engagement of said well casing from said first slips to said second slips. 13'. A device as recited in claim 12 in which said mandrel is in two sections and includes threaded joint means interconnecting said sections,

whereby rotation of the first of said sections relative to the second of said sections in one direction causes separation of said joint means,

said first drag block means, said first slips and esaid packing means being on said first section, said second slips and said second drag block means being on said second section, means coupling said second section to said first slips,

whereby said first slips when in said gripping engagement with said well casing resist rotation of said second section so that rotation of said rst section relative to said second section in said one direction causes separation of said second section from said first section, and including means for separating said first expansion member from said first slips and said second expansion member from said second slips when said joint means is so separated upon movement of said mandrel,

whereby said packer is retrievable with said first and second slips released.

14. In combination with a tubing string, a well packer comprising:

an elongated mandrel attached to said tubing string and adapted for insertion in a well bore, said mandrel including a rst section, a second section, and a threaded joint interconnecting said iirst and second sections, a first drag block means on said first section, means holding said first drag block means against axial movement relative to said first section, a first slip means on said first section, means holding said first slip means against axial movement relative to said first section, a first expansion member on said first section,

said first expansion member being movable axially of said mandrel in one direction for expanding said first slip means outwardly into engagement with the wall of a well casing for holding said mandrel therein, `and movable in the opposite direction for releasing said first slip means, a compressible elastomeric packing means on said first section and slidable axially relative thereto, a first abutment means at one end of said packing means, a second abutment means at the opposite end of said packing means, a second slip means on said second section, a second expansion member,

said second expansion member being movable in said opposite direction for expanding said second slip means outwardly into gripping engagement with a well casing, and movable in said one direction for releasing said second slip means, a second drag block means on said second section adjacent said second slip means,

said second slip means and said second drag block means being movable axially relative to said sccond section, means on said mandrel for moving said first abutment means in said one direction for applying a force through said packing means for moving said first expansion member in said one direction for so expanding said first slip means and causing said first slip means to grip a well casing, and compressing said packing means between said first and second abutment means for expanding said packing means outwardly into sealing engagement with said well casing, said tubing string being elongatable in response to the imposition of a predetermined force thereon in the `opposite direction resulting from a predetermined load in said opposite direction on said packing means when so compressed applied through said first abutment means to said mandrel and from said mandrel to said tubing string, for moving said mandrel and said packing means while so compressed in said opposite direction and moving said second expansion member in said opposite direction for expanding said second slip means outwardly into gripping engagement with said well casing and causing said first expansion member to move in said opposite direction for releasing said first slip means, means rotationally coupling said second section with said first slip means for causing said second section to be held stationary by said first slip means when said first slip means is expanded outwardly to grip a well casing,

whereby upon rotation of said first threaded joint can be separated, and means for releasing said first slip means upon movement of said threaded joint,

thereby permitting retrieval of said well packer with said first and second slip means retracted. 15. A well packer apparatus for use in a well bore comprising: a mandrel adapted for connection to a running-in string extending to the top of the well bore, elastomeric packing means encircling said mandrel for packing olf the well bore, said packing means being normally retracted and expansible outwardly in response to compression thereof, means on said mandrel for shifting said elastomeric packing means in one longitudinal direction, first slip and expander means adjacent one end of said packing means for anchoring said packing means and said mandrel against movement along the well bore in one longitudinal direction in response to shifting of said packing means by said means on said mandrel in said one longitudinal direction, means on said mandrel for shifting said packing means in the opposite longitudinal direction away from said first slip and expander means while said packing means is packing off the Well bore in response to a fiuid pressure acting in said longitudinal direction, and second slip and expander means adjacent the other end of said packing means activated by shifting of said packing means and said mandrel in said opposite longitudinal direction for limiting shifting movement of said packing means and said mandrel in said opposite longitudinal direction.

section said References Cited UNITED STATES PATENTS 2,998,072 8/1961 Crowe 166--134 3,195,642 7/ 1965 Conrad 166-134 3,236,309 2/1966 Conrad 166-134 3,299,955 1/ 1967 Page 166-134 JAMES A. LEPPINK, Primary Examiner 'Eggo UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,469,628 Dated Sept- 30, 1969 Inventor(s) Martn B. Conrad It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 12, line 2, change "cluding" to cludes line 55, after l'section'l (first occurrence) insert a comma; same line, before II Il sectlon (second occurrence) msert second Column 14, 11ne 35, change l'alppos'ce" to opposite line 58, change l'esaid" to said SI'G-N'ED MID SEALED JUN 9 1970 EAL) Attest:

WILLIAM E." Bamm, JR. Edward M' memhern" Gonnissioner of Patents Attesting Officer 

